This invention relates to an insertion mechanism, a caulking mechanism and an insertion/caulking device used for inserting and fastening an L-shaped corner piece to a concave outward flange in order to reinforce a corner portion of an open edge of duct when manufacturing an air-conditioning duct having a rectangular cross section.
FIG. 8 shows an oblique view of a partly manufactured air-conditioning duct. A duct body 1 is formed having a rectangular cross-section using a surface-treated iron plate, in which a side plate 1a has at its open edge an integral outward flange 3 at right angles to the side plate 1a, and the flange 3 has at its outside end an integral bent portion 6 at right angles to the flange 3 so as to be formed a channel. A convex groove 7 having a circular-arc cross section, which extends straight in parallel with and at the same height as a tip edge of the bent portion 6 and projects to the outside as illustrated by FIG. 8, is formed on the side plate 1a.
In the duct having the above-mentioned structure, an L-shaped corner piece 5 is pushed to a corner portion 4 and an upper end of the bent portion 6 is crimped so as to fasten the corner piece 5 as shown in FIG. 9, in order to fill the corner portion 4 between adjoining flanges and reinforce coupling of the flanges 3 each other.
A vertically movable L-shaped pressure member, for example, is provided in a conventional insertion mechanism for inserting the corner piece 5 so that the corner piece 5 is pushed in the corner portion 4 by making the pressure member move down.
In a conventional caulking mechanism, swingable caulking claws are arranged in V-shaped positions and upper end portions of both-sides bent portions 6 of the corner piece 4 are trued up and caulked by swinging the caulking claws.
The insertion mechanism and the caulking mechanism are installed independently of each other. The insertion mechanism is removed from the corner piece 5 after pushing the L-shaped corner piece 5 in the concave flange 3 by the insertion mechanism, and the bent portion 6 is then caulked by the caulking mechanism independently.
However, mutual vertical deviations between the side plates 1a, dispersions of bending angles and/or dispersions of angles between the flange 3 and the side plate 1a due to twisting of the flange 3 etc. sometimes occur in the duct body 1 which is assembled into the rectangular shape by the side plates 1a. In case when inserting or caulking the corner piece 5 to such the duct body 1, faulty insertion or faulty caulking would occur in the structure of merely pushing the corner piece from above position or merely caulking it from side position as in case of conventional one. Further, efficiency is poor when inserting and caulking works are carried out by separate mechanisms independently.
An object of this invention is to improve assembly accuracy and a work efficiency in the work for assembling the corner piece.
Another object of this invention is to enable operation of the insertion mechanism and the caulking mechanism in sequence according to a work stroke by a single stretching action of one drive actuator, so as to further improve the work efficiency.